Photographing system

ABSTRACT

A photographing system includes a lens apparatus having an image blur correcting device configured to correct and/or reduce image blur caused by vibration, a vibration sensor for detecting vibration applied to the lens apparatus, a position detecting device configured to detect a position change of the lens apparatus, and a controlling device configured to control the image blur correcting device using a detection signal of the position detecting device. The photographing system reduces the influence of low frequency noise of a vibration sensor, while maintaining the quality of a vibration isolation function of the lens apparatus.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a photographing system provided with alens apparatus having an image blur correction function.

Recent years have seen an advance in the technology of producing lensapparatuses for television cameras with increased zoom ratio and focallength. However, use of this technology results in image blurring,particularly at telephoto focal length, due to vibration transmitted toa lens apparatus from the wind or from the floor on which the lensapparatus is placed. To address this drawback, a television camera lensapparatus has been developed which is provided with an image blurcorrection function for compensating image blurring by driving a portionof a lens group included in the lens apparatus.

Generally, a frequency of vibration applied to a television camera lensapparatus ranges from 1 Hz to 15 Hz. A vibration sensor, which can beused for detecting vibration applied to a lens apparatus, transmits asignal containing a signal component that is output in accordance withthe vibration and a low frequency noise component of approximately 0.1Hz. To remove this low frequency noise component from the output signalof the vibration sensor, a high pass filter is provided in a controlunit of a vibration proof lens group. However, since a frequency band ofthe vibration component to be reduced and that of the low frequencynoise component are close to each other, a case often occurs where thehigh pass filter fails to remove low frequency noise componentssufficiently. This causes the vibration proof lens group to be driven bythe noise components that pass through the high pass filter, resultingin an unintended blurred image of a subject. This is well known as adrift phenomenon that can cause a subject to be viewed moving slowlywithin a frame.

In consideration of the foregoing, Japanese Patent Laid-Open No.1992-56831 discusses a technique for eliminating or reducing the effectof low frequency noise by inactivating an image blur correction functionwhen a vibration sensor output satisfies a predetermined condition.However, since vibration sensors output an analogue signal, lowfrequency noise components vary largely depending on the individualvibration sensors. This can cause a significant difficulty in setting acondition by which a signal component is determined to be or not to be alow frequency noise component. As a condition for distinguishing a lowfrequency noise component, a small amplitude value can be set, forexample. In this case, however, it cannot be possible to detect everylow frequency noise component, leaving the low frequency noise problemunsolved. On the other hand, when a large amplitude value is set, avibration component to be reduced can be misrecognized as a noisecomponent, which reduces the efficiency of a vibration proof function.

SUMMARY OF THE INVENTION

A photographing system according to an exemplary embodiment of thepresent invention includes: a lens apparatus having an image blurcorrecting device configured to correct and/or reduce image blur; avibration sensor for detecting vibration applied to the lens apparatus;a position detecting device configured to detect a position change ofthe lens apparatus; and a controlling device configured to cause theimage blur correcting device to perform image blur correction and/orreduction in accordance with a correction amount which is based on anoutput value of the vibration sensor, when an output value of theposition detecting device is greater than or equal to a predeterminedvalue, and for causing the image blur correcting device not to performimage blur correction and/or reduction, when the output value of theposition detecting device is smaller than a predetermined value.

In the photographing system according to an exemplary embodiment of thepresent invention, an output signal of the position detecting device canbe used for controlling the image blur correcting device, so that adrift phenomenon, which is caused by a low frequency noise componentfrom the vibration sensor, can be eliminated or reduced withoutdeteriorating quality of a vibration isolation function.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a general configuration of aphotographing system according to a first exemplary embodiment.

FIG. 2 is a flowchart illustrating a first exemplary embodiment.

FIG. 3 is a flowchart illustrating a second exemplary embodiment.

FIG. 4 is a flowchart illustrating a third exemplary embodiment.

FIG. 5 is a graph illustrating a relation between an image blurcorrection frequency band and a noise determining frequency.

FIG. 6 is a flowchart illustrating a fourth exemplary embodiment.

DESCRIPTION OF THE EMBODIMENTS

The following description of at least one exemplary embodiment is merelyillustrative in nature and is in no way intended to limit the invention,its application, or uses.

Processes, techniques, apparatus, and materials as known by one ofordinary skill in the relevant art may not be discussed in detail butare intended to be part of the enabling description where appropriate.

In all of the examples illustrated and discussed herein any specificvalues should be interpreted to be illustrative only and non limiting.Thus, other examples of the exemplary embodiments could have differentvalues.

Notice that similar reference numerals and letters refer to similaritems in the following figures, and thus once an item is defined in onefigure, it may not be discussed for following figures.

First Exemplary Embodiment

Referring to FIGS. 1 and 2, a first exemplary embodiment will bedescribed in detail. FIG. 1 is a block diagram illustrating a generalconfiguration of a photographing system provided with a lens apparatus20 and a platform 30. The lens apparatus 20 has an image blur correctionfunction. The platform 30 has a detecting device configured to detect apanning operation and a tilting operation of the lens apparatus 20. Thelens apparatus 20 also has the following components including: avibration sensor 1 for detecting vibration applied to the lens apparatus20; a high pass filter for removing a low frequency noise componentcontained in an output signal of the vibration sensor 1; an arithmeticcircuit 3 for amplifying an output of the high pass filter 2 andconverting an angular velocity signal from the vibration sensor 1 into asignal representing an angle; an A/D converter 4 for feeding an outputsignal received from the arithmetic circuit 3 to a CPU 8; an image blurcorrection lens group 5 for correcting and/or reducing image blur on animage plane by shifting a portion of the lens group in a directionperpendicular to an optical axis; an actuator 6 for driving the imageblur correction lens group 5; a position detecting device 7 fordetecting a position of the image blur correction lens group 5; a CPU 8for calculating a control signal of the image blur correction lens group5 on the basis of an output of the A/D converter 4; a D/A converter 9for converting a signal calculated by the CPU 8 into an analogue signal;a driving circuit 10 for driving the actuator 6; and a panning detectingdevice 11 for detecting a panning operation of the platform 30 andoutputting a digital signal representing a value which is proportionalto the amount of panning performed in the panning operation. The panningdetecting device 11 outputs reference position data when thephotographing system is turned on and thereafter outputs relativeposition data based on the reference position data. The panningdetecting device 11 includes, for example, a rotary encoder and acounter.

The flowchart of FIG. 2 illustrates a processing sequence of the CPU 8of the lens apparatus 20. Operations of the platform 30 include apanning operation associated with movement in a horizontal direction anda tilting operation associated with movement in a vertical direction.The image blur correction lens group 5 is driven in horizontal and/orvertical directions. In this exemplary embodiment, for simplicity, onlya panning operation of the platform 30 and a horizontal driving of theimage blur correction lens group 5 will be described. When the lensapparatus 20 is turned on through a camera (not shown), the CPU 8initializes a register, a memory, or the like in the CPU 8, at STEP S1.At STEP S2, the CPU 8 initializes a counter (Count=0) for measuring atime period during which an output of the panning detecting device 11 isheld constant. This counter prevents an image blur correction flag (tobe hereinafter described) from being unstable, such as repeatedlyshifting between a set state and a clear state. At STEP S3, two buffers(PanData, PanBuffer) for output data of the panning detecting device 11are initialized (PanData=0, PanBuffer=0). Initialization operations arecompleted thus far, and the CPU 8 proceeds to normal operations startingfrom STEP S4. Output data of the panning detecting device 11, which isstored in the buffer (PanData) in a preceding sampling process, istransferred to the buffer for panning output data (PanBuffer), at STEPS4. At STEP S5, current output data of the panning detecting device 11is read and stored in the buffer (PanData). If the values of the twobuffers (PanData, PanBuffer) are equal, it is indicated that no panningoperation has been performed and that no unintended vibration has beenapplied to the lens apparatus 20. If the values of the buffers (PanData,PanBuffer) are not equal, it is indicated that the platform 30 iscurrently engaged in an operation through an operator or that a changeis taking place in accordance with vibration which is not intended by anoperator. At STEP S6, the values of PanData and PanBuffer are compared.If the two values are equal, indicating that neither a panning operationnor unintended vibration has occurred, a counter value (Count) ischecked, at STEP S7. If the counter value (Count) is greater than orequal to a value corresponding to a predetermined time period Ta,indicating that a state in which unintended vibration is not applied haslasted for Ta or longer, the CPU 8 determines that image blur to bereduced has not occurred. In that case, the image blur correction flagis cleared (Flag=0), at STEP S8, and the processing proceeds to STEPS13. This image blur correction flag is indicative of whether or notimage blur correction can be executed. If the image blur correction flagis set, image blur correction is performed by driving the image blurcorrection lens group 5 in accordance with an output of the vibrationsensor 1. If the image blur correction flag is clear (Flag=0), the imageblur correction lens group 5 is operatively connected to a referenceposition and image blur correction is not performed, regardless of anoutput of the vibration sensor 1.

If, in STEP S7, the counter value (Count) is found to be smaller than avalue corresponding to a predetermined time period Ta, indicating thatthe time period Ta during which unintended vibration is not applied hasnot elapsed, the CPU 8 determines that image blur to be reduced hasoccurred. In this case, the counter value is incremented(Count=Count+1), at STEP S9, and the image blur correction flag is set,at STEP S10. Then, the processing proceeds to STEP S13.

If, in STEP S6, the values of the two buffers (PanData, PanBuffer) arefound to be not equal, indicating that a panning operation has beenperformed or that unintended vibration has been applied, the processingproceeds to STEP S11. At STEP S11, the counter is cleared (Count=0), andthe image blur correction flag is set, at STEP S12.

Then, a state of the image blur correction flag is determined, at STEPS13. If the image blur correction flag is clear, the processing proceedsto STEP S14, and image blur correction control data (Control) is set tobe reference position data (Control=0). Then, the image blur correctioncontrol data (Control) is output to the D/A converter 9, at STEP S16.

If, in STEP S13, the image blur correction flag is found to be set, theprocessing proceeds to STEP S15. At STEP S15, vibration components to bereduced are extracted from the outputs of the vibration sensor 1 and thepanning detecting device 11 so that the image blur correction controldata (Control) is calculated. This calculated image blur correctioncontrol data (Control) is output to the D/A converter, at STEP S16.

Hereafter, the processing of STEP S4 through STEP S16 is repeated untilthe lens apparatus 20 is turned off.

In this exemplary embodiment, a case is described in which an angularvelocity signal of the vibration sensor 1 is converted into a signalrepresenting an angle, using the arithmetic circuit 3 constituted byhardware. However, this conversion operation can also be implemented bysoftware. In addition, the vibration sensor 1 can not only be an angularvelocity sensor but also be an acceleration sensor such as a linearacceleration sensor. Moreover, the position detecting device accordingto this exemplary embodiment is configured to detect panning and tiltingoperations of a lens apparatus. However, the position detecting devicecan also be a rotary encoder or a potentiometer for detecting theposition of a focus lens or a zoom lens contained in a lens apparatus.These configuration modifications can likewise be made in the followingexemplary embodiments.

Second Exemplary Embodiment

Referring to FIG. 3, the second exemplary embodiment according to atleast one exemplary embodiment will be described. Since this exemplaryembodiment has the same general configuration as the first exemplaryembodiment, the description thereof will be omitted. The flowchart ofFIG. 3 illustrates a processing procedure of the CPU 8 according to thisexemplary embodiment. The processing of STEP S101 through STEP S105 isthe same as that of STEP S1 through STEP S5 of FIG. 1, and thus thedescription thereof will also be omitted. At STEP S106, the values oftwo buffers (PanData, PanBuffer) are compared. If the absolute value ofa difference between PanData and PanBuffer is smaller than apredetermined value A, the processing proceeds to STEP S107. If theabsolute value of the difference between PanData and PanBuffer isgreater than or equal to the predetermined value A, the processingproceeds to STEP S111.

Since the processing of STEP S107 through STEP S116 is the same as thatof STEP S7 through STEP S16, the description thereof will be omitted.Hereafter, the processing of STEP S104 through STEP S116 is repeateduntil the lens apparatus 20 is turned off.

Third Exemplary Embodiment

Referring to FIG. 4, the third exemplary embodiment according to atleast one exemplary embodiment will be described. Since this exemplaryembodiment has the same general configuration as the first exemplaryembodiment, the description thereof will be omitted. The flowchart ofFIG. 4 illustrates a processing procedure of the CPU 8 according to thisexemplary embodiment. When the lens apparatus 20 is turned on through acamera (not shown), the CPU 8 initializes a register, a memory, or thelike within the CPU 8, at STEP S201. Then, the CPU 8 clears an imageblur correction flag (Flag=0), thereby completing the initializationoperations and proceeding to normal operations starting from STEP S203.An output of the vibration sensor 1 (hereinafter referred to as avibration sensor output) is read through the A/D converter and set asSensorData, at STEP S203. At STEP S204, an output of the panningdetecting device 11 (hereinafter referred to as a panning detectingdevice output) is read and set as PanData. At STEP S205, the panningdetecting device output is input to a frequency estimation function, sothat an output signal frequency is calculated. The calculated frequencycan be set as PanFreq. This frequency estimation function outputs thehighest frequency among frequencies (frequency component) contained ininput data. Although the frequency estimation function is implemented bysoftware in this exemplary embodiment, it can also be implemented byhardware.

At STEP S206, a difference signal (Sabun) corresponding to a differencebetween the vibration sensor output (SensorData) and the panningdetecting device output (PanData) is calculated and stored in a buffer.

When an operator applies vibration to the lens apparatus 20 on purpose,such as panning a camera, there is no substantial phase differencebetween the vibration sensor output and the panning detecting deviceoutput. Therefore, a difference signal to be calculated will besynchronized with the vibration applied by the operator. In a case whereunintentional vibration can be applied to the lens apparatus 20, thereis no substantial phase difference between the vibration sensor outputand the panning detecting device output, and the difference signal to becalculated will be synchronized with the unintended vibration. Thus, ineither case where the lens apparatus 20 receives intended vibration orwhere the lens apparatus 20 receives unintended vibration, there is nosubstantial phase difference between the vibration sensor output and thepanning detecting device output, resulting in a difference signal thatis synchronized with the vibration. This allows the CPU 8 to distinguisha noise component from the vibration sensor 1 by examining thedifference signal.

In a case where no vibration can be applied to the lens apparatus 20,the panning detecting device 11 maintains an output of a constant value.On the other hand, the vibration sensor outputs a low frequency signalwhich is a noise component, in spite of the absence of vibration.Therefore, a calculation of a difference between the vibration sensoroutput and the panning detecting device output yields a valuecorresponding to a noise component of the output signal from thevibration sensor 1. If the panning detecting device output issynchronized with neither the vibration sensor output nor the differencesignal between the vibration sensor output and the panning detectingdevice output, the vibration sensor output can be determined to benoise. In this manner, using an output of the panning detecting device11, such as a rotary encoder, which produces an equivalently smallamount of noise, a difference signal between a vibration sensor outputand a panning detecting device output is monitored. This enables it tobe determined whether an output signal from the vibration sensor 1 is avibration component or a noise component more accurately, compared witha case where only a vibration sensor that produces an output containinga noise component is used.

At STEP S207, the difference signal (Sabun) is input to a frequencyestimation function, and the calculated frequency can be set asSabunFreq.

At STEP S208, the frequency of the output signal of the panningdetecting device 11 and a lowest frequency fa of an image blurcorrection frequency band are compared. This lowest frequency fa of animage blur correction frequency band is the lowest frequency in the bandof frequencies for which image blur correction is performed. Thus, on asignal, which can have a frequency lower than fa, no image blurcorrection is performed. If the frequency of the panning detectingdevice output signal (PanFreq) is lower than fa, then the differencesignal frequency (SabunFreq) and a noise determination frequency(f_noise) are compared, at STEP S209. This noise determination frequency(f_noise) is the highest frequency of a low frequency noise componentoutput from the vibration sensor 1. An output with a frequency higherthan the noise determination frequency (f_noise) is regarded as avibration component to be reduced which is detected by the vibrationsensor 1. If the difference signal frequency (SabunFreq) is lower thanthe noise determination frequency (f_noise), the difference signalcorresponds to a low frequency noise component of the output signal fromthe vibration sensor 1. In this case, the image blur correction flag iscleared (Flag=0), at STEP S210, and the processing proceeds to STEPS213.

If the difference signal frequency (SabunFreq) is found to be higherthan or equal to the noise determination frequency (f_noise) in STEPS209, the difference signal is determined to be a vibration component tobe reduced. In this case, the image blur correction flag is set(Flag=1), at STEP S211, and the processing proceeds to STEP S213.

If, in STEP S208, the frequency of the panning detecting device outputsignal (PanFreq) is found to be higher than or equal to the lowestfrequency fa of the image blur correction frequency band, the panningdetecting device output signal is determined to be a vibration componentto be reduced. In this case, the image blur correction flag is set(Flag=1), at STEP S212, and the processing proceeds to STEP S213.

In at least one exemplary embodiment the lowest frequency fa of theimage blur correction frequency band is set to be lower than the noisedetermination frequency (f_noise), as illustrated in FIG. 5. The lowestfrequency fa of the image blur correction frequency band is set to bethe lowest frequency of a vibration component that can be detected bythe panning detecting device 11. This enables image blur correction tobe performed on any vibration component. In addition, by setting thenoise determination frequency (f_noise) to be the highest frequency of anoise component that can be output by the vibration sensor 1, a driftphenomenon due to low frequency noise can be eliminated or reduced.

In STEP S213, if the image blur correction flag is found to be clear(Flag=0), the image blur correction control data is set to be thereference position data (Control=0), at STEP S214. Then, the image blurcorrection control data (Control) is output to the D/A converter 9, atSTEP S216.

If the image blur correction flag is found to be set (Flag=1) in STEPS213, image blur correction control data (Control) is calculated on thebasis of the vibration sensor output signal read through the high passfilter 2, arithmetic circuit 3, and A/D converter 4, at STEP S215. Thecalculated data is output to the D/A converter 9, at STEP S216.Hereafter, the processing of STEP S203 through STEP S216 will berepeated until the lens apparatus 20 is turned off.

As with the cases of the first and second exemplary embodiments, thephotographing system according to this exemplary embodiment can alsoprevent an image blur correction flag from being unstable, such asrepeatedly shifting between a set state and a clear state. For example,a counter can be employed for measuring a time period during which afrequency of the panning detecting device output signal (PanFreq) stayslower than the lowest frequency fa of an image blur correction frequencyband. Another counter can also be used for measuring a time periodduring which a difference signal frequency (SabunFreq) stays lower thana noise determination frequency (f_noise).

Fourth Exemplary Embodiment

Referring now to FIG. 6, the fourth exemplary embodiment according to atleast one exemplary embodiment will be described. Since the firstexemplary embodiment and this exemplary embodiment have the same generalconfiguration, the description thereof will be omitted. The flowchart ofFIG. 6 illustrates a processing procedure of the CPU 8. The processingof STEP S301 through STEP S303 is the same as that of STEP S201 throughSTEP S203 of FIG. 4, and thus the description thereof will be omitted.At Step S304, an output of the vibration sensor 1 (SensorData) is inputto a frequency estimation function, and the calculated frequency of thevibration sensor output signal can be set as SensorFreq. This frequencyestimation function is configured to output the highest frequency amongfrequencies (frequency component) contained in input data. The frequencyestimation function can be implemented either by software or by hardwareto yield the same result. At STEP 305, an output of the panningdetecting device 11 is read and set as PanData. The processing of STEPS306 through STEP S307 is the same as that of STEP S206 through STEPS207, and thus the description thereof will be omitted. At STEP S308,the frequency of the vibration sensor output signal (SensorFreq) and alowest frequency fa of an image blur correction frequency band arecompared. The lowest frequency fa of the image blur correction frequencyband is the lowest frequency in the band of frequencies for which imageblur correction is performed. Therefore, image blur correction is notperformed on signals whose frequencies are lower than fa, such as lowfrequency noise components output from the vibration sensor 1. If, inSTEP S308, the frequency of the vibration sensor output signal(SensorFreq) is found to be lower than the lowest frequency fa of theimage blur correction frequency band, the processing proceeds to STEPS309. At STEP S309, a difference signal frequency (SabunFreq) and anoise determination frequency (f_noise) are compared. This noisedetermination frequency (f_noise) is the highest frequency of a lowfrequency noise component output from the vibration sensor 1. An outputof a frequency higher than the f_noise is a vibration component which isdetected by the vibration sensor 1 and can be reduced. If the differencesignal frequency (SabunFreq) is lower than the noise determinationfrequency (f_noise), the difference signal is a noise component of theoutput signal of the vibration sensor 1. In this case, the image blurcorrection flag is cleared (Flag=0), at STEP S310, and the processingproceeds to STEP S313. If, in STEP S309, the difference signal frequency(SabunFreq) is found to be higher than or equal to the noisedetermination frequency (f_noise), the difference signal is determinedto be a vibration component corresponding to vibration which has beenapplied to the lens apparatus 20 and can be reduced. In this case, theimage blur correction flag is set, at STEP S311, and the processingproceeds to STEP S313.

If, in STEP S308, the frequency of the vibration sensor output signal(SensorFreq) is found to be higher than or equal to the lowest frequencyfa of the image blur correction frequency band, the vibration sensoroutput signal is determined to be a vibration component to be reduced.In this case, the image blur correction flag is set (Flag=1), at STEPS312, and the processing proceeds to STEP S313.

Hereafter, the processing of STEP S313 through STEP S316 is the same asthat of STEP S213 through STEP S216, and thus the description thereofwill be omitted. The processing of STEP S303 through STEP S316 isrepeated until the lens apparatus 20 is turned off.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all modifications, equivalent structures and functions.

This application claims the priority of Japanese Patent Application No.2005-117134 filed Apr. 14, 2005, which is hereby incorporated byreference herein in its entirety.

1. A photographing system comprising: a lens apparatus having an imageblur correcting device configured to correct and/or reduce image blur; avibration sensor for detecting vibration applied to the lens apparatus;a position detecting device configured to detect a position change ofthe lens apparatus; and a controlling device configured to cause theimage blur correcting device not to perform image blur correction, whena difference signal between an output signal of the vibration sensor andan output signal of the position detecting device has a frequency lowerthan a noise determination frequency which is specific to the vibrationsensor, wherein the controlling device causes the image blur correctingdevice not to perform image blur correction, when the highest frequencyof the output signal of the position detecting device is lower than thelowest frequency of a predetermined image blur correction frequency bandand when the difference signal has a frequency lower than the noisedetermination frequency which is specific to the vibration sensor. 2.The photographing system of claim 1, wherein the lowest frequency of theimage blur correction frequency band is lower than the noisedetermination frequency.
 3. The photographing system of claim 1, whereinthe controlling device causes the image blur correcting device not toperform image blur correction, when the highest frequency of the outputsignal of the vibration sensor is lower than the lowest frequency of apredetermined image blur correction frequency band and when thedifference signal has a frequency lower than the noise determinationfrequency which is specific to the vibration sensor.
 4. Thephotographing system of claim 1, wherein the controlling device causesthe image blur correcting device not to perform image blur correction,when the difference signal continuously has a frequency lower than thenoise determination frequency which is specific to the vibration sensor,for a predetermined time period.
 5. The photographing system of claim 1,wherein the position detecting device detects at least either a panningoperation or a tilting operation of the lens apparatus.
 6. Thephotographing system of claim 1, wherein the position detecting devicecomprises a rotary encoder.
 7. A photographing system comprising: a lensapparatus having an image blur correcting device configured to correctand/or reduce image blur; a vibration sensor for detecting vibrationapplied to the lens apparatus; a position detecting device configured todetect a position change of the lens apparatus; and a controlling deviceconfigured to cause the image blur correcting device not to performimage blur correction, when a difference signal between an output signalof the vibration sensor and an output signal of the position detectingdevice has a frequency lower than a noise determination frequency whichis specific to the vibration sensor, wherein the controlling devicecauses the image blur correcting device not to perform image blurcorrection, when the highest frequency of the output signal of thevibration sensor is lower than the lowest frequency of a predeterminedimage blur correction frequency band and when the difference signal hasa frequency lower than the noise determination frequency which isspecific to the vibration sensor.
 8. A photographing system comprising:a lens apparatus having an image blur correcting device configured tocorrect and/or reduce image blur; a vibration sensor for detectingvibration applied to the lens apparatus; a position detecting deviceconfigured to detect a position change of the lens apparatus; and acontrolling device configured to cause the image blur correcting devicenot to perform image blur correction, when a difference signal betweenan output signal of the vibration sensor and an output signal of theposition detecting device has a frequency lower than a noisedetermination frequency which is specific to the vibration sensor,wherein the controlling device causes the image blur correcting devicenot to perform image blur correction, when the difference signalcontinuously has a frequency lower than the noise determinationfrequency which is specific to the vibration sensor, for a predeterminedtime period.